how do I tell if I have sure grip in my 3.91?

[Gizmo327]

from what I researched, if im correct my 73 Cuda will either have sure grip or non sure grip. Without taking it apart is there a way that I figure out which type of rear end I have?

[70 Challenger Lover]

You can raise the rear end with both tires off the ground. In neutral if you spin one tire, both should turn in the same direction. If they turn in opposite directions, no sure grip it's an open carrier. This assumes it is working properly. If the clutches are wiped out inside, that test probably won't work.

[JS29]

You can raise the rear end with both tires off the ground. In neutral if you spin one tire, both should turn in the same direction. If they turn in opposite directions, no sure grip it's an open carrier. This assumes it is working properly. If the clutches are wiped out inside, that test probably won't work.

Also if someone holds one tire and if you can turn the other, no sure-grip. 

[RUNCHARGER]

Easy way is to hop in the car, drive in front of a Chevy guys house and light it up. Two black marks=Sure grip, One black mark=standard differential.

[1 Wild R/T]

Easy way is to hop in the car, drive in front of a Chevy guys house and light it up. Two black marks=Sure grip, One black mark=standard differential.

This is the recommended test procedure per the service manual...  Trust Me... 

[MoparLeo]

You only need to jack up one side. If you can turn the wheel in the air it is not a Sure-grip. Simple. Done.

[7E-Bodies]

@RUNCHARGER now that is freakin hilarious! The only thing I'd change is to make it a Prius owners house.